This invention relates to curettes of the type used for such purposes as removal of cancerous and non-cancerous skin growths.
The technique of curettage is routinely used by dermatologists to separate diseased skin or skin lesions from normal skin. The instrument used to perform curettage on the skin is termed a dermal curette. Commonly used dermal curettes include, among others, the Fox curette and the Piffard curette, both of which are manual stainless steel instruments having a loop-form cutter or blade and an elongated handle for manipulation of the blade by the user. These are regarded as permanent, reusable curettes, in that because of their expense, they would not be economical for single-use application.
Disposable curettes are also available and are generally suitable for their intended purpose. However, they often may have a different feel to the user, and therefore may require practice before the user who is accustomed to a reusable curette, such as the Fox or the Piffard, can become proficient in their use. The reason for this is that normal tissue has a different feel under the cutting action of the curette than lesional tissue. The user who is more sensitive to this difference in feel will also be more proficient at removal of lesions, since the sensitivity to feel will allow more complete removal of lesional tissue with less incursion into normal tissue.
This sort of sensitivity comes with practice and experience, and can be disrupted by differences in design, materials and structure, as between different curettes. Accordingly, practitioners would normally prefer to confine their use of curettes to a single type. The need to choose a single type of curette could, however be obviated by a disposable curette having the same feel, heft, weight and balance as a reusable curette.
Of course, the disposability of a curette is entirely a matter of economics, and any curette may be regarded as disposable if the user is unconcerned about its cost. As a practical matter, however, many physicians, including dermatologists for example, use curettes routinely and therefore cannot treat reusable curettes as disposables, nor can they escape the cost trade-off between presently available reusable and disposable curettes.
The cost of a reusable curette is relatively high compared to available disposable curettes, and the instrument therefore must serve the user over a relatively long term in order to justify its cost. Typically, after a period of use, the cutting blade of a reusable curette will become dull and must be sent out for resharpening. In addition, there are the costs of time, material, equipment, energy and labor involved in the repeated cleaning and sterilization of reusable curettes. Still further, a practitioner who sees patients in more than one examination room, or in multiple office locations, will require duplicate sets of such instruments to ensure that a set of suitable, freshly sterilized, sharp curettes are always available in each examination room or office location while others are being sterilized or sharpened. As may be appreciated, the costs associated with curette procurement and maintenance can be substantial.
Of course, many of the logistical and financial drawbacks attendant to the use of reusable curettes disappear entirely if one instead chooses to use only disposable curettes. However, disposable curettes also have their associated drawbacks.
Specifically, presently available disposable curettes are comprised of an inseparable handle and stainless steel blade assembly which is intended to be disposed of entirely after a single use. Thus, although sharpening, cleaning or sterilization costs do not arise, the full replacement cost of the curette, while much lower than the cost of a reusable curette, must be paid with each use.
Another disadvantage of some disposable curettes is the use of a rather thin gauge material for the loop-form cutting blade. A curette blade formed of such thin gauge material may tend to deform under mechanical pressure and therefore will not have a consistent feel in use. Thus, an unduly thin gauge curette blade may be more difficult to control and use, regardless of the experience of the user.
Additionally, presently available disposable curettes may tend to be less sharp than either a new or resharpened reusable curette. This may be due to mechanical limitations encountered in the sharpening of the thin gauge blade material.
A final disadvantage of presently available disposable curettes is the lightweight plastic handle which does not have the same feel or shape as the stainless steel handle of a reusable curette. No choice of handle is available since these disposable curettes are all manufactured with the same handle style.
Among the prior art relating to curettes in general are U.S. Pat. Nos. 2,569,237, 2,617,420, 2,651,068, 4,044,770, 4,785,796, 4,791,924, 4,932,957 and 5,116,346, as well as British Patent 1,192,654. Several of these patents disclose curette instruments with a loop-form blade or a non-cutting loop-form working end. Other examples of related art include U.S. Pat. Nos. 1,089,018, 3,502,082 and 4,414,974.